1. Field of the Invention
The present invention relates to an abseil rescue device, particularly to an abseil rescue device having a brake actuated by a hydraulic cylinder, which allows a user to operate the rescue device with a light hand control.
2. Description of Related Art
In U.S. patent application Ser. No. 09/112,534, as shown in FIG. 5, an abseil rescue system with a velocity control system disclosed by the inventor comprises a pair of holders 10, 11, a pair of retarders 12, 13, and a pair of brakes 14, 15. The holders 10, 11, the retarders 12, 13, and the brakes 14, 15 are hingedly connected with one another by a shaft 18 such that grippers at an end thereof (not shown clearly) can execute to clamp an escape rope 26. The grippers on the holders 11, 12 are positioned oppositely and enclose the escape rope while the holders 11, 12 are closed to abut against each other. The grippers on the retarders 12, 13 and the brakes 14, 15 are alternately disposed one another beside the grippers on the holders 10, 11, respectively, such that the escape rope 26 can be clamped to form a shape of S by the grippers while the rescue device is operated. The retarders 12, 13 at the other ends thereof attach a safety cord 16 for putting around a user's waist. Thus, the weight of the user causes the retarders 12, 13 to held together and the grippers thereon press against the rescue rope 26 such that an uniform friction can be applied onto the rescue rope 26. The brakes 14, 15 at the other ends thereof attach a pulling cord 17 to be pulled by the user such that the grippers thereon press against the rescue rope 26 either and an additional friction can be generated onto the rescue rope 26. Thus, the descent velocity of the user can be controlled by the hand force. But, some persons are unable to apply their hand forces completely while they are nervous in case of an emergency condition. Furthermore, women and children usually have a less hand force to operate the rescue system. Consequently, it still results in poor braking effect under a condition of an inadequate hand force such that an unsteady descent velocity is unavoidable to occur.